This paper provides a summary of recent data for real-world fuel consumption of HDVs—specifically, tractor-trailers—in three regions: the United States, China, and the
European Union. The primary objectives of this study are: to provide a brief overview of the market and fleet characteristics of tractor trailers in the U.S., China, and the EU and discuss the policy measures enacted in each region to promote increased HDV fuel efficiency; to describe the various types of fuel consumption data and their respective
usefulness in assessing the impacts of fuel efficiency and GHG regulations; to synthesize all of the publically available real-world fuel consumption data in each region and illustrate the widespread lack of data across jurisdictions and underscore the need for further data collection and research in this area; and to lay the foundation for future research that can more thoroughly analyze how the rates of fuel-saving technology deployment differ from region to region and how this translates into differing rates of efficiency improvement over time.